A factory pays its apprentices a monthly stipend that increases by a fixed amount each month. The first month’s stipend is ₹5,000, and the increase each month is ₹250. After certain number of months, the average stipend paid up to that month becomes ₹8,500.
(i) Find the number of months after which the average stipend reaches ₹8,500.
(ii) Determine the total amount paid to an apprentice during this period.
(iii) Calculate the average stipend over the next three months following this period.